A Sooke, B.C. family’s walk on the beach turned into a paleontology expedition when they stumbled upon a rare find: a 25-million-year-old bird fossil embedded in a slab of rock.

The daughter spotted a bone buried in a rock slab that had broken off from a nearby cliff and her brother helped carry the fossil off the beach, with their father bringing it straight to the Royal BC Museum in Victoria for identification.

The fossil has since been verified by researchers as a previously unknown species of plotopterid, a long-extinct family of flightless diving birds whose wings functioned as flippers – just like penguins.

“It was basically the first useful bird fossil that had been found in more than 100 years in that area,” said museum bird expert Gary Kaiser. “Bird fossils are very, very rare because bird bones are light and fragile.”

He said most plopterid fossils that have been found in Japan and the U.S. have measured more than two metres long – but the fossil found in Sooke is from a much smaller bird, about as big as a duck.

With the help of his colleague Junya Watanabe, from Kyoto University in Japan, the newly discovered species of bird was dubbed Stemec suntokum, which means “long-necked waterbird” in the language of the local T’Sou-ke Nation.

The fossil has been moved to the Royal BC Museum’s collection and Kaiser, Watanabe and Marji Johns, the museum’s paleontology collections manager, have published a paper announcing the species.

“It’s extraordinary to think this bird bone survived predation, burial, earthquakes, plate tectonics, heating, alteration, potential dissolution, uplift and weathering,” said Johns.

Experts say the plopterid family went extinct shortly after the bird was fossilized due to changing temperatures in the Pacific Ocean that led to a scarcity of food for the diving birds. Sea lions and seals may have preyed on the plopterids as well.